The present invention relates to tube reinforcements, and more particularly to a tube reinforcement designed for complex tubular structures and having at least one deflecting wing for holding the reinforcement in place within the tube.
Tube structures are used in many applications, such as in automobile A-pillars, B-pillars, C-pillars, the hinge pillar area, rocker panels, the wheel hub area, motor rails, and similar structures. In these tube structures, it is often desirable to place reinforcements at selected areas for added strength. In more complex tube structures, however, it can be difficult to place a reinforcement at a desired location because of bends and varying cross-sectional areas in the tube cavity. Any reinforcement inserted into the end such a structure needs to be small enough to fit through the tube cavity along the length of the tube, including the bends and smaller cross-sectional areas, and yet still be able to stay in place at a desired reinforcement location, even if the cross-sectional area at the desired location is larger. Currently known reinforcements cannot be adjusted to accommodate varying tube cross-sectional areas, and as a result the reinforcement will either be too large to pass through smaller areas of the tube to reach a desired location or too small to stay secured at the desired location once it is positioned.
Structural foam can be used to create a reinforcement assembly that conforms to the tube cavity and that provides even dispersement of forces along the foam. Placing and keeping the foam at the desired reinforcement location before the foam has been expanded and cured, however, still can be difficult for the reasons noted above.
There is a need for a reinforcement assembly that is small enough to fit around curves and through smaller tube dimensions in a tube structure, yet will not shift position once it is placed at a desired location within the tube cavity, even if the tube structure is moved before the structural foam on the assembly has been expanded and cured.
The present invention is directed to a tube reinforcement assembly for reinforcing complex tube structures, particularly tube structures having bends and/or varying cross-sectional areas in the tube cavity. The assembly includes a carrier and one or more deflecting wings arranged around the carrier. The carrier is preferably smaller than the smallest cross-sectional area of the structure to be reinforced to ensure that the assembly can move through the tube structure""s cavity to reach a desired reinforcement location. The deflecting wings are moveable between an extended position and a compressed position and are biased in the extended position, ensuring that the spring forces in the deflecting wings will hold the assembly at a given location once it is placed there, regardless of the tube cavity cross-sectional area at that location. An expandable structural foam layer is disposed on one surface of at least one wing, and preferably on both surfaces of the wing. When the inventive reinforcement assembly is inserted into a tube structure, the deflecting wings move toward their compressed position if the tube cavity size decreases, allowing the assembly to pass through tighter areas and around curves in the tube cavity, if needed, without getting trapped.
Once the reinforcement assembly is placed at the desired reinforcement location, the spring-biased wings press against the inner walls of the tube cavity to hold the assembly in place before the foam is expanded. The wings act as retainers so that the assembly will not shift from the desired position if the tube structure is moved before processing has been completed (e.g. before the structural foam has been expanded to fill the tube structure). The tube structure and the reinforcement assembly is then heated so that the structural foam expands to fill at least a portion of the tube cavity so that the assembly is rigidly held in place. If the structural foam is applied to both surfaces of each wing, one foam layer will expand between the wing and the inner wall of the tube and the other foam layer will expand between the wing and the carrier of the reinforcement assembly. In one embodiment, the expanded foam bonds to the inner wall. As a result, the present invention can reinforce complexly-shaped tubes simply and efficiently.